Sinker or web holder control



June l, 1937. R. H. LAwsoN ET Al.

SINKER OR WEB HOLDER CONTROL Filed April 9, 1929 2 Sheets-Sheet l WIT.

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` SINKER 0R WEB HOLDER CONTROL l Filed. April 9, 1929 2 Sheets-Sheet 2 INVENTORS: RoBERT HLAWSON, ARTHUR N. CLoUTIER,

B Y *Worf Patented June 1, 1937 UNITED STATES sINKER on WEB HOLDER CONTROL Robert H. Lawson, Pawtucket, and Arthur N.

Cloutier, Lonsdale, R. I., assignors to Hemphill Company, Central Falls, R. I., a corporation of Massachusetts Application April 9, 1929, Serial No. 353,835

9 Claims.

The present invention has to do with the control of the sinkers or web holders in a knitting machine of the independent needle type such as disclosed in the patent to Hemphill 933,443,

Sept. 7, 1909.

It has long been recognized as desirable to hold the sinkers forward against the fabric in such a manner that the said sinkers may yield or give slightly under stress of the fabric though normally held yieldingly against the same. The object has heretofore been accomplished by the useof a spring band surrounding the sinkers but the use of a spring band is not entirely satisfactory especially when reverse plating. The

sinkers, uniformly urged forward toward the needle circle by the spring band, do not permit the use of flopper cams to give to certain of the sinkers an earlier or differentiated movement with relation to others of the sinkers, necessary when reverse vplating with sinkers.

In the drawings:

Fig. 1 is an inverted plan view of the sinker cap used in connection with one form of the invention;

Fig. 2 is a view in side elevation of the said sinker cap;

Fig. 3 is a View, partly line 3 3, Fig. 1;

Fig. 4 isa view, in section, taken on line 4-4, Fig. 1;

Fig. 5 is a View similar to Fig. 2 of another formof the invention;

Fig. 6 is a view similar to Fig. 1, of said other form; and

Fig. 7 is a sectional View taken on line 'I-l, Fig. 6, showing the relative positions assumed by the sinkers and needles while they are traversing .the non-knitting or idle portionof the raceway.

'Ihe numeral I represents the sinker cap as 40 a whole,2 and 3 fixed cams for normally controlling the sinker movements at the knitting point both for circular and reciprocating knitting, which said cams 2, 3 are secured to an overhanging flange I of the sinker cap. Sectional cams 4 overlapping at 4 constitute a continuation of the cam 3 and are mounted for movements to and from the forming fabric as about to be described. A raceway 5 is defined by walls 5 the outer of which constitutes a cam integral with or secured to the flange I while the other or inner Wall forms the outer surfaces of the cams 4. Sinkers 6 are provided with butts I which are received in and guided by the said raceway 5. The cams 4 as Well as 5 the cam 3 are reduced in thickness where they overlap at 3 and 4', and are received in the space or groove 9 between the butts 'I and the vertical edges I0 of the sinkers 6. The said cams 4 have surfaces 8 at their inner edges or margins which cam surfaces 8 are normally in in section, taken on (Cl. (i6-108)V constant engagement with the vertical edges III of the sinkers, and by means presently to be described, maintain the said sinkers in yielding engagement with their wales.

The sinkers when passing the fixed cams 2, 3 move in a normal path and knit in the usual manner in conjunction with the needles (not shown). After passing the knitting point, i. e., after the old stitches have been knocked over by the sinkers cammed forward to their innermost limit by the tip I2 of either cam 2 in reciprocating knitting, and by the uppermost as shown in Fig. 1 in circular knitting, the said sinkers are permitted, as usual, to retract slightly as at I3 thereby to relieve the stitches held on the open needle latches from undue strain that might otherwise cause a rupture of the stitches or some of them. Thereafter in the knitting cycle the needles and sinkers maintain the same relative positions, i. e., with the old stitch on the latch of each needle and held below the sinker nibs II.

If the cams 4 are not controlled as about to be described, streaks occasionally show in the fabric due to the fact that certain of the sinkers Y' are frictioned more than adjacent sinkers, and remain forward against the fabric thereby tensioning their wales and robbing or pulling thread from adjacent wales which are not so tensioned by their sinkers.

The form of the invention disclosed in Figs. 1-4 has the particular object in View of avoiding the formation of such streaks in the knit fabric and to that end provides for yieldingly holding or maintaining the sinkers in forward position against the forming fabric,`whereby the position of the sinkers as they pass around the needle circle through the non-knitting portion of the same, will not bedependent upon the relative frictioning of the sinkers but the said sinkers will be uniformly maintained or guided in their idle path of traverse between courses.

The means for yieldingly maintaining the sinkers in forward Web-,engaging position is disclosed specifically in Fig. 3 of the drawings wherein rods I4 are received in and guided by holes I5 provided in arms I B upstanding from brackets I'I attached to the sinker cap I in any convenient manner as by screws. There are four such brackets shown in Fig. l one at each end of both sectional cams 4, 4. Each rod I4, as aforesaid guided by its bracket, has a block or shoe I8 threaded onto the inner end thereof, which block is adapted to engage a pin I9 upstanding from one of the cams 4 adjacent one end thereof. The normal engagement of the block or shoe I8 with a pin I9 is maintained by means of a coiled spring 20 which surrounds the rod I4 and at one end is in engagement with the outer arm I6 while at the other end presses against a collar 2l adjustably held on the rod by means of a set screw 22.V The coiled spring 28 by exerting pressureY against the collar 2|y maintains the block or shoe I8 constantly and yieldingly against a pin I9 which normally seatsl within a recess 23 provided in the flange I of the sinker cap I. Each pin I8 is under spring pressure in the same manner and the cams 4, 4 are consequently constantly urging the sinkers forward against the forming fabric, thereby resulting in a constant and uniform pressure or tension being exerted by the sinkers on their wales especially so when the sinkers are passing through the idle or non-knitting portion of the raceway, i. e., after the old stitches have been knocked over for one course and until the said sinkers again reach the mouth-piece for the next course of knitting. The even tensioning of the wales results in the knitting of uniform fabric without streaks.

In Fig. 4 a sinker is shown which is supported by the stitch ring 24 of the cylinder 25 at its forward end, and by the sinker head 26 beyond or outside of the needle cylinder 25.

In the second disclosed form of the invention, Figs. 5 7, the numeral 58 indicates the sinker cap in general which cap has a ilange 5I acting as a support for the sinker actuating cams. Around the inner circular edge of the flange 5I is clamped a spring band or cam 52 which is held in place by the overlapping, xed cam '53 as shown in Fig. 6. Opposite the mouthpiece (not shown) are positioned two thin xed cams 554, 55 normally adapted to actuate the sinkers at the knitting point. Superposed, or rather, in the assembled positions, underneath the said xed cams 54, 55 are two cams 56, 51 which are yieldingly urged toward the axis of the sinker cap by leaf springs 58, 59 respective- 1y. The spring 58 is attached to the sinker cap 58 by means of a screw or other means and at a point substantially midway between the ends of the aforesaid cam 56. The spring 58 consists of two wings or arms extending to each side of the point of attachment, the outer or free ends of which spring arms engage over pins 68, 6l respectively depending from radial extensions 6,2, 63 projecting outwardly from the cam 56. The extensions 62, 63 pass through slots or cutouts in the sinker cap 58. The cam 51 has similarly projecting portions or radial extensions 64, 65, the latter only of which has a depending pin 66 engaged by the leaf spring k59 thereby to urge the said cam 51 in a, more or less, radial direction toward the sinker cap axis. The cams 56, 51 where they overlap the fixed, thin cams 54, 55 are cut away as indicated bythe dotted lines 61, 61 adjacent the ends of the said fixed cams 54, 55 shown partly in dotted lines, whereby the cams throughout are of substantially uniform thickness.

Springs '68,69 attached to the cap 56 at one end, engage by their free ends pins 10, 1l depending from radial projections 12, 13 of cams 14, 15 which projections 12, 13 extend through slots in the sinker cap as do the other cam projections. At 16 are shown the overlapping ends of the cam sections 51, 14, 15, and 56, one end oi each said cam dovetailing into the adjacent end of the other.

Between the spring band or ring 52 and the sectional cams 51, V14, 15 and 56 is provided a raceway 11 for the sinkers or web-.holders as they pass around with the needles from course to course. The sinkers 18 have butts 19 which latter are received in the raceway 11.

In order to reverse plate the sinkers are given earlier forward movements in a manner similar to that disclosed in the patent to Stewart 1,602,786, Oct. l2, 1926, and the yarns are reversed in a manner similar to that disclosed in Fig. 6 of the said patent. The sinkers, or rather selected ones of them, have the earlier movements imparted to them through the agency of flopper cams 88 pivoted at 80' and held away from the sinkers by springs 8l attached to a bracket 82 connected to the sinker cap 58, but urged forward to a position to engage the sinkers as desired which flopper cams at such times impart an earlier forward movement to their sinkers by engaging additional butts 83 thereon, which butts are positioned at different levels to be engaged by their ilopper'cams 88. The said flopper cams, six in number, have pins 84, three of which project in an upward direction from, while the other three depend from their respective flopper cams. The pins 84 are engaged by suitable levers or other selectively controlled means (not shown). per cams, and parts for controlling the movements of the same, are not, in themselves, a part of the present invention, but do combine in a novel manner with the yieldingly mounted, sectional cams normally urging the sinkers to a forward position through the agency of the several springs 58, 59, 68, 69.

Referring to Fig. '7 a view, partly in section, is shown to more clearly disclose' the necessity for having the sinkers held in a forward position against the forming fabric. In Ythe said Figure 7 a needle 85 and companion sinker 18 are in the relative positions they assume and hold when travelling in the circular portion of the'raceway 11 between stitch forming movements at the mouth-piece where the sinker cams 53, 54, 56 and Ilopper cams 88 determine the character of stitch to be knit by each sinker in cooperation with its neeedle. At such times, i. e., between courses,

the needles and sinkers are in the relative positions shown in Fig. 7, and the last drawn stitches or loops are hanging upon the open latches 86 and within the throats 81 of the sinkers which latter are, as shown in Fig. 7, in a forward position with their throats substantially in alignment with the backs of adjacent needles or slightly radially inward thereof in which position they maintain the stitchesor loops under tension. If the sinkers are held in the position, Fig.'7,unyieldingly the stitches or loops will necessarily be maintained under stress tending to rupture the yarn oppositely tensioned by the adjacent needles and sinkers and this is more especially true when tight stitches are being knit as the short stitchesbreak under the strain exerted bythe sinkers and companion needles. As will be evident from inspection of Fig. 7 and also the Stewart patent, the reverse plating sinkers are provided with short noses, i. e., with little overhang as compared with the ordinary sinker 8 of the Stewart patent. The short noses 88 herein disclosed permit yarn held thereby to slip off if the stitch is loosely held with the result that the needle latch adjacent thereto does not subsequently clear in the normal manner but the nee- P' dle tucks cr accumulates loops.

The devices of the present invention overcome the mentioned difficulties by holding the short noses or nibs of the reverse plating sinkers forward against the fabric thereby preventing the The sinkers, floploops or stitches from slipping off the said nibs, and furthermore, when knitting a tight stitch, the sinkers are permitted to yield or recede from the needles sufficiently to prevent rupture of the held stitches or loops.

The operation may be briefly summarized as follows:

In the first form, disclosed in Figs. 1-4, the sinkers traverse the raceway in the direction of the arrow, Fig. 1, first moving outwardly in a radial direction away from the axis, thereafter again moving toward the said axis to the stitch knock-over point, then receding slightly to relieve the stitches, and finally remaining in the latter position with respect to the axis until the aforesaid cycle of movements for the following course of knitting is repeated. Throughout the circular part of the raceway the sectional cams yieldingly urge the sinkers forward against the stitches thus maintaining the forming wales under even tension. The sectional cams do not control the sinkers at the knitting point or from the time they are retracted and again advanced to knock-over the stitches, but resume control only after the sinkers retract to relieve the stitches which retraction immediately follows the knocking over of the old stitches by the sinkers.

In the second form disclosed in Figs. 5-7, the sinkers traverse the circular path in the raceway as they do in the first form except that sinkers are not retracted after the knock-over of the stitches or old loops, but remain in their forward web-en-l gaging position though permitted to yield through the agency of the sectional cams. The sinkers are relieved from the influence of the spring cams as they leave the circular part of the raceway, whereupon the cam 53 engages the sinkers, and in conjunction with a flopper cam and/or a cam 54 or a cam 55 retracts and again advances the said sinkers thereby assisting in the formation of stitches for the following course of knitting.

Although the spring cams disclosed in Figs. 1-4, inclusive, are primarily intended to be used for plain knitting, and while the corresponding spring cams disclosed in Figs. 5, 6, and 7 are primarily intended to be used for reverse plating or other knitting requiring special actuation or control of the sinkers or some of them; nevertheless the special cams, Figs. 1 4 inclusive, may be used in conjunction with specially controlled sinkers and the spring cams of Figs. 5, 6, and 7 may be used for the knitting of plain fabric or plain plated fabric if desired.

While, in the foregoing description, the sinkers have been referred to as moving in the raceway, such movement is relative, the sinkers themselves moving in a machine of the rotary needle cylinder type, and the cap moving or rotating in a machine of the stationary needle cylinder type.

The effect of maintaining the sinkers in a forward position by the means hereinbefore described, is to hold the nibs of the sinkers over the sinker wales of the newly drawn stitches, i. e., stitches drawn by the cooperation of needles and sinkers immediately prior to the knocking over thereof by the knocking-over cam, thus preventing the formation of tuck or drop stitches. Furthermore, by yieldingly maintaining the sinkers in a forward position, as described, more uniform fabric is knitted.

The sectional cams or their equivalent, are useful, where springs would not be suitable, e. g., wherever selective, differential movements of sinkers are desired for any purpose as for reverse plating herein described with relation to the second form disclosed, and also for sinker drop stitch work.

While specic terms have been employed to designate the essential elements of the present disclosure, it is to be understood that the scope of the said invention is not otherwise limited than by the claims appended, modifications of the parts and arrangements being within the intendment and scope thereof.

We claim:

1. A sinker cap for use in a circular knitting machine, comprising sinkers and sectional cams therein for the control of the said sinkers throughout the knitting and non-knitting portions of the camway, and means acting through the sectional cams for yieldingly controlling the movements of the sinkers in a radial direction substantially throughout the non-knitting portions of the camway.

2. A sinker cap for use in circular machines of the independent needle type, cams therein for controlling the sinker movements so that stitches may be formed, and means for guiding the sinkers between successive stitch forming movements, said means including sectional cams urged forward or toward the needle circle, and maintaining the sinkers in a relatively forward position excepting where such sinkers are retracted and again advanced.

3. A sinker cap provided with a raceway for sinkers, bodily movable cams adapted to act upon sinkers between stitch forming movements thereof and yieldingly hold them in forward position to prevent the knitting of ruck or drop stitches.

4. A sinker cap provided with a raceway for sinkers, one wall of the. raceway being divided into sections, each said section being yieldingly held in forward position, and thereby adapted to maintain sinkers yieldingly against the forming fabric.

5. In a sinker cap for use in circular knitting machines, cams adapted to guide the sinkers and impart stitch forming movements thereto, and other cams adapted to contact with the sinkers, in combination with means acting upon the said other cams yieldingly to maintain the said other cams in forward positions to hold the nibs of the sinkers over the sinker wales of newly drawn stitches.

6. A sinker cap having therein opposing cam surfaces providing a raceway therebetween, one of the cam surfaces being divided into a series of sections, each section being yieldingly urged forward or toward the needles.

7. A circular sinker cap having therein opposing cam surfaces providing a raceway therebetween, one of the cam surfaces being divided into sections, each section being yieldingly urged forward or toward the needles.

8. In a circular knitting machine sinker cap, a sinker raceway bounded on one side by a sectional cam, said cam being yieldingly mounted and adapted to press sinkers forward toward the needle circle to maintain their nibs over the sinker wales of newly drawn stitches.

9. In a circular sinker cap for use in circular knitting machines of the independent needle type, a sectional cam, the sections of which are yieldingly urged to move in a substantially radial direction toward the sinker axis thereby to maintain the nibs of the sinkers over the sinker wales of newly drawn stitches.

YROBERT H. LAWSON.

ARTHUR N. CLOUTIER. 

